OTP Generator & Validator
Generate and validate One-Time Passwords (OTP), supporting TOTP, HOTP, and simple OTP.
Time-based One-Time Password (TOTP)
Generates time-based OTP codes, refreshing automatically every 30 seconds
OTP Types Explained
TOTP (Time-based)
• Time-based One-Time Password
• Updates every 30-60 seconds
• Requires time synchronization
• Suitable for mobile apps
• Common algos: SHA1, SHA256
HOTP (Counter-based)
• Counter-based One-Time Password
• Increments counter on each use
• No time sync needed
• Suitable for hardware tokens
• Need to maintain counter state
Simple OTP
• Random number generation
• For temporary verification
• Simple and fast
• Lower security
• Good for SMS/Email verification
Security Advice
Key Management:
- Use strong random key generators
- Store keys securely, avoid leaks
- Rotate keys periodically
- Use encrypted transmission for keys
Usage Environment:
- Ensure server time accuracy
- Implement anti-brute-force mechanisms
- Limit verification attempts
- Log validation failures